All around me architects and business managers are beginning to mandate that internal software applications be built (and sometimes rebuilt) as microservices so that we can reuse them and compose applications more quickly. I do admit that the idea of a curated catalog of well designed microservices is attractive. Contrary to all the buzz that… Continue reading
Posts by Daniel Watrous
Bulid a multi-server Hadoop cluster in OpenStack in minutes
In a previous post I demonstrated a method to deploy a multi-node Hadoop cluster using Vagrant and Ansible. This post builds on that and shows how to deploy a Hadoop cluster with an arbitrary number of slave nodes in minutes on OpenStack. This process makes use of the OpenStack orchestration layer HEAT to provision the… Continue reading
Install and configure a Multi-node Hadoop cluster using Ansible
I’ve recently been involved with several groups interested in using Hadoop to process large sets of data, including use of higher level abstractions on top of Hadoop like Pig and Hive. What has surprised me most is that no one is automating their installation of Hadoop. In each case that I’ve observed they start by… Continue reading
Configuration of python web applications
Hopefully it’s obvious that separating configuration from application code is always a good idea. One simple and effective way I’ve found to do this in my python (think bottle, flask, etc.) apps is with a simple JSON configuration file. Choosing JSON makes sense for a few reasons: Easy to read (for humans) Easy to consume… Continue reading
Encryption of secrets in source code (AESCrypt + Ansible)
The more I automate, the more I have to answer the question of how to manage my secrets. Secrets that frequently come up include: SSH key pairs SSL private keys Credentials for external resources, such as databases and SaaS integrations Before cloud, when server resources were not ephemeral, these could be managed manually when the… Continue reading
Increase Munin Resolution to sub-minute
I previously explained how to get one-minute resolution in Munin. The process to get sub-minute resolution in Munin is more tricky. The main reason it’s more tricky is that cron only runs once per minute, which means data must be generated and cached in between cron runs for collection when cron runs. In the case… Continue reading
Increase Munin Resolution to One Minute
I’ve recently been conducting some performance testing of a PaaS solution. In an effot to capture specific details resulting from these performance tests and how the test systems hold up under load, I looked into a few monitoring tools. Munin caught my eye as being easy to setup and having a large set of data… Continue reading
Understanding Munin Plugins
Munin is a monitoring tool which captures and graphs system data, such as CPU utilization, load and I/O. Munin is designed so that all data is collected by plugins. This means that every built in graph is a plugin that was included with the Munin distribution. Each plugin adheres to the interface (not a literal… Continue reading
Managed services in Stackato
This post is an extension of Managed services in CloudFoundry and follows the discussion of external services integration. The echo service and python service broker implementation are deployed using the documented procedure for Stackato. If necessary, you can get a Stackato instance up and running quickly. The result should be two apps deployed as shown… Continue reading
User provided services in CloudFoundry
This post builds on the discussion of Managed Services in CloudFoundry and covers the first of the two methods for using unmanaged services in CloudFoundry. It makes use of the Python echo service and Python service broker API implementation used previously. Manually provision the service This method assumes that an existing service has been provisioned… Continue reading